1/* 2 * drivers/uio/uio.c 3 * 4 * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de> 5 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> 6 * Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de> 7 * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com> 8 * 9 * Userspace IO 10 * 11 * Base Functions 12 * 13 * Licensed under the GPLv2 only. 14 */ 15 16#include <linux/module.h> 17#include <linux/init.h> 18#include <linux/poll.h> 19#include <linux/device.h> 20#include <linux/slab.h> 21#include <linux/mm.h> 22#include <linux/idr.h> 23#include <linux/sched.h> 24#include <linux/string.h> 25#include <linux/kobject.h> 26#include <linux/cdev.h> 27#include <linux/uio_driver.h> 28 29#define UIO_MAX_DEVICES (1U << MINORBITS) 30 31static int uio_major; 32static struct cdev *uio_cdev; 33static DEFINE_IDR(uio_idr); 34static const struct file_operations uio_fops; 35 36/* Protect idr accesses */ 37static DEFINE_MUTEX(minor_lock); 38 39/* 40 * attributes 41 */ 42 43struct uio_map { 44 struct kobject kobj; 45 struct uio_mem *mem; 46}; 47#define to_map(map) container_of(map, struct uio_map, kobj) 48 49static ssize_t map_name_show(struct uio_mem *mem, char *buf) 50{ 51 if (unlikely(!mem->name)) 52 mem->name = ""; 53 54 return sprintf(buf, "%s\n", mem->name); 55} 56 57static ssize_t map_addr_show(struct uio_mem *mem, char *buf) 58{ 59 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr); 60} 61 62static ssize_t map_size_show(struct uio_mem *mem, char *buf) 63{ 64 return sprintf(buf, "0x%lx\n", mem->size); 65} 66 67static ssize_t map_offset_show(struct uio_mem *mem, char *buf) 68{ 69 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK); 70} 71 72struct map_sysfs_entry { 73 struct attribute attr; 74 ssize_t (*show)(struct uio_mem *, char *); 75 ssize_t (*store)(struct uio_mem *, const char *, size_t); 76}; 77 78static struct map_sysfs_entry name_attribute = 79 __ATTR(name, S_IRUGO, map_name_show, NULL); 80static struct map_sysfs_entry addr_attribute = 81 __ATTR(addr, S_IRUGO, map_addr_show, NULL); 82static struct map_sysfs_entry size_attribute = 83 __ATTR(size, S_IRUGO, map_size_show, NULL); 84static struct map_sysfs_entry offset_attribute = 85 __ATTR(offset, S_IRUGO, map_offset_show, NULL); 86 87static struct attribute *attrs[] = { 88 &name_attribute.attr, 89 &addr_attribute.attr, 90 &size_attribute.attr, 91 &offset_attribute.attr, 92 NULL, /* need to NULL terminate the list of attributes */ 93}; 94 95static void map_release(struct kobject *kobj) 96{ 97 struct uio_map *map = to_map(kobj); 98 kfree(map); 99} 100 101static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, 102 char *buf) 103{ 104 struct uio_map *map = to_map(kobj); 105 struct uio_mem *mem = map->mem; 106 struct map_sysfs_entry *entry; 107 108 entry = container_of(attr, struct map_sysfs_entry, attr); 109 110 if (!entry->show) 111 return -EIO; 112 113 return entry->show(mem, buf); 114} 115 116static const struct sysfs_ops map_sysfs_ops = { 117 .show = map_type_show, 118}; 119 120static struct kobj_type map_attr_type = { 121 .release = map_release, 122 .sysfs_ops = &map_sysfs_ops, 123 .default_attrs = attrs, 124}; 125 126struct uio_portio { 127 struct kobject kobj; 128 struct uio_port *port; 129}; 130#define to_portio(portio) container_of(portio, struct uio_portio, kobj) 131 132static ssize_t portio_name_show(struct uio_port *port, char *buf) 133{ 134 if (unlikely(!port->name)) 135 port->name = ""; 136 137 return sprintf(buf, "%s\n", port->name); 138} 139 140static ssize_t portio_start_show(struct uio_port *port, char *buf) 141{ 142 return sprintf(buf, "0x%lx\n", port->start); 143} 144 145static ssize_t portio_size_show(struct uio_port *port, char *buf) 146{ 147 return sprintf(buf, "0x%lx\n", port->size); 148} 149 150static ssize_t portio_porttype_show(struct uio_port *port, char *buf) 151{ 152 const char *porttypes[] = {"none", "x86", "gpio", "other"}; 153 154 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER)) 155 return -EINVAL; 156 157 return sprintf(buf, "port_%s\n", porttypes[port->porttype]); 158} 159 160struct portio_sysfs_entry { 161 struct attribute attr; 162 ssize_t (*show)(struct uio_port *, char *); 163 ssize_t (*store)(struct uio_port *, const char *, size_t); 164}; 165 166static struct portio_sysfs_entry portio_name_attribute = 167 __ATTR(name, S_IRUGO, portio_name_show, NULL); 168static struct portio_sysfs_entry portio_start_attribute = 169 __ATTR(start, S_IRUGO, portio_start_show, NULL); 170static struct portio_sysfs_entry portio_size_attribute = 171 __ATTR(size, S_IRUGO, portio_size_show, NULL); 172static struct portio_sysfs_entry portio_porttype_attribute = 173 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL); 174 175static struct attribute *portio_attrs[] = { 176 &portio_name_attribute.attr, 177 &portio_start_attribute.attr, 178 &portio_size_attribute.attr, 179 &portio_porttype_attribute.attr, 180 NULL, 181}; 182 183static void portio_release(struct kobject *kobj) 184{ 185 struct uio_portio *portio = to_portio(kobj); 186 kfree(portio); 187} 188 189static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr, 190 char *buf) 191{ 192 struct uio_portio *portio = to_portio(kobj); 193 struct uio_port *port = portio->port; 194 struct portio_sysfs_entry *entry; 195 196 entry = container_of(attr, struct portio_sysfs_entry, attr); 197 198 if (!entry->show) 199 return -EIO; 200 201 return entry->show(port, buf); 202} 203 204static const struct sysfs_ops portio_sysfs_ops = { 205 .show = portio_type_show, 206}; 207 208static struct kobj_type portio_attr_type = { 209 .release = portio_release, 210 .sysfs_ops = &portio_sysfs_ops, 211 .default_attrs = portio_attrs, 212}; 213 214static ssize_t name_show(struct device *dev, 215 struct device_attribute *attr, char *buf) 216{ 217 struct uio_device *idev = dev_get_drvdata(dev); 218 return sprintf(buf, "%s\n", idev->info->name); 219} 220static DEVICE_ATTR_RO(name); 221 222static ssize_t version_show(struct device *dev, 223 struct device_attribute *attr, char *buf) 224{ 225 struct uio_device *idev = dev_get_drvdata(dev); 226 return sprintf(buf, "%s\n", idev->info->version); 227} 228static DEVICE_ATTR_RO(version); 229 230static ssize_t event_show(struct device *dev, 231 struct device_attribute *attr, char *buf) 232{ 233 struct uio_device *idev = dev_get_drvdata(dev); 234 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event)); 235} 236static DEVICE_ATTR_RO(event); 237 238static struct attribute *uio_attrs[] = { 239 &dev_attr_name.attr, 240 &dev_attr_version.attr, 241 &dev_attr_event.attr, 242 NULL, 243}; 244ATTRIBUTE_GROUPS(uio); 245 246/* UIO class infrastructure */ 247static struct class uio_class = { 248 .name = "uio", 249 .dev_groups = uio_groups, 250}; 251 252/* 253 * device functions 254 */ 255static int uio_dev_add_attributes(struct uio_device *idev) 256{ 257 int ret; 258 int mi, pi; 259 int map_found = 0; 260 int portio_found = 0; 261 struct uio_mem *mem; 262 struct uio_map *map; 263 struct uio_port *port; 264 struct uio_portio *portio; 265 266 for (mi = 0; mi < MAX_UIO_MAPS; mi++) { 267 mem = &idev->info->mem[mi]; 268 if (mem->size == 0) 269 break; 270 if (!map_found) { 271 map_found = 1; 272 idev->map_dir = kobject_create_and_add("maps", 273 &idev->dev->kobj); 274 if (!idev->map_dir) 275 goto err_map; 276 } 277 map = kzalloc(sizeof(*map), GFP_KERNEL); 278 if (!map) 279 goto err_map_kobj; 280 kobject_init(&map->kobj, &map_attr_type); 281 map->mem = mem; 282 mem->map = map; 283 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); 284 if (ret) 285 goto err_map_kobj; 286 ret = kobject_uevent(&map->kobj, KOBJ_ADD); 287 if (ret) 288 goto err_map; 289 } 290 291 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) { 292 port = &idev->info->port[pi]; 293 if (port->size == 0) 294 break; 295 if (!portio_found) { 296 portio_found = 1; 297 idev->portio_dir = kobject_create_and_add("portio", 298 &idev->dev->kobj); 299 if (!idev->portio_dir) 300 goto err_portio; 301 } 302 portio = kzalloc(sizeof(*portio), GFP_KERNEL); 303 if (!portio) 304 goto err_portio_kobj; 305 kobject_init(&portio->kobj, &portio_attr_type); 306 portio->port = port; 307 port->portio = portio; 308 ret = kobject_add(&portio->kobj, idev->portio_dir, 309 "port%d", pi); 310 if (ret) 311 goto err_portio_kobj; 312 ret = kobject_uevent(&portio->kobj, KOBJ_ADD); 313 if (ret) 314 goto err_portio; 315 } 316 317 return 0; 318 319err_portio: 320 pi--; 321err_portio_kobj: 322 for (; pi >= 0; pi--) { 323 port = &idev->info->port[pi]; 324 portio = port->portio; 325 kobject_put(&portio->kobj); 326 } 327 kobject_put(idev->portio_dir); 328err_map: 329 mi--; 330err_map_kobj: 331 for (; mi >= 0; mi--) { 332 mem = &idev->info->mem[mi]; 333 map = mem->map; 334 kobject_put(&map->kobj); 335 } 336 kobject_put(idev->map_dir); 337 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); 338 return ret; 339} 340 341static void uio_dev_del_attributes(struct uio_device *idev) 342{ 343 int i; 344 struct uio_mem *mem; 345 struct uio_port *port; 346 347 for (i = 0; i < MAX_UIO_MAPS; i++) { 348 mem = &idev->info->mem[i]; 349 if (mem->size == 0) 350 break; 351 kobject_put(&mem->map->kobj); 352 } 353 kobject_put(idev->map_dir); 354 355 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { 356 port = &idev->info->port[i]; 357 if (port->size == 0) 358 break; 359 kobject_put(&port->portio->kobj); 360 } 361 kobject_put(idev->portio_dir); 362} 363 364static int uio_get_minor(struct uio_device *idev) 365{ 366 int retval = -ENOMEM; 367 368 mutex_lock(&minor_lock); 369 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL); 370 if (retval >= 0) { 371 idev->minor = retval; 372 retval = 0; 373 } else if (retval == -ENOSPC) { 374 dev_err(idev->dev, "too many uio devices\n"); 375 retval = -EINVAL; 376 } 377 mutex_unlock(&minor_lock); 378 return retval; 379} 380 381static void uio_free_minor(struct uio_device *idev) 382{ 383 mutex_lock(&minor_lock); 384 idr_remove(&uio_idr, idev->minor); 385 mutex_unlock(&minor_lock); 386} 387 388/** 389 * uio_event_notify - trigger an interrupt event 390 * @info: UIO device capabilities 391 */ 392void uio_event_notify(struct uio_info *info) 393{ 394 struct uio_device *idev = info->uio_dev; 395 396 atomic_inc(&idev->event); 397 wake_up_interruptible(&idev->wait); 398 kill_fasync(&idev->async_queue, SIGIO, POLL_IN); 399} 400EXPORT_SYMBOL_GPL(uio_event_notify); 401 402/** 403 * uio_interrupt - hardware interrupt handler 404 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer 405 * @dev_id: Pointer to the devices uio_device structure 406 */ 407static irqreturn_t uio_interrupt(int irq, void *dev_id) 408{ 409 struct uio_device *idev = (struct uio_device *)dev_id; 410 irqreturn_t ret = idev->info->handler(irq, idev->info); 411 412 if (ret == IRQ_HANDLED) 413 uio_event_notify(idev->info); 414 415 return ret; 416} 417 418struct uio_listener { 419 struct uio_device *dev; 420 s32 event_count; 421}; 422 423static int uio_open(struct inode *inode, struct file *filep) 424{ 425 struct uio_device *idev; 426 struct uio_listener *listener; 427 int ret = 0; 428 429 mutex_lock(&minor_lock); 430 idev = idr_find(&uio_idr, iminor(inode)); 431 mutex_unlock(&minor_lock); 432 if (!idev) { 433 ret = -ENODEV; 434 goto out; 435 } 436 437 if (!try_module_get(idev->owner)) { 438 ret = -ENODEV; 439 goto out; 440 } 441 442 listener = kmalloc(sizeof(*listener), GFP_KERNEL); 443 if (!listener) { 444 ret = -ENOMEM; 445 goto err_alloc_listener; 446 } 447 448 listener->dev = idev; 449 listener->event_count = atomic_read(&idev->event); 450 filep->private_data = listener; 451 452 if (idev->info->open) { 453 ret = idev->info->open(idev->info, inode); 454 if (ret) 455 goto err_infoopen; 456 } 457 return 0; 458 459err_infoopen: 460 kfree(listener); 461 462err_alloc_listener: 463 module_put(idev->owner); 464 465out: 466 return ret; 467} 468 469static int uio_fasync(int fd, struct file *filep, int on) 470{ 471 struct uio_listener *listener = filep->private_data; 472 struct uio_device *idev = listener->dev; 473 474 return fasync_helper(fd, filep, on, &idev->async_queue); 475} 476 477static int uio_release(struct inode *inode, struct file *filep) 478{ 479 int ret = 0; 480 struct uio_listener *listener = filep->private_data; 481 struct uio_device *idev = listener->dev; 482 483 if (idev->info->release) 484 ret = idev->info->release(idev->info, inode); 485 486 module_put(idev->owner); 487 kfree(listener); 488 return ret; 489} 490 491static unsigned int uio_poll(struct file *filep, poll_table *wait) 492{ 493 struct uio_listener *listener = filep->private_data; 494 struct uio_device *idev = listener->dev; 495 496 if (!idev->info->irq) 497 return -EIO; 498 499 poll_wait(filep, &idev->wait, wait); 500 if (listener->event_count != atomic_read(&idev->event)) 501 return POLLIN | POLLRDNORM; 502 return 0; 503} 504 505static ssize_t uio_read(struct file *filep, char __user *buf, 506 size_t count, loff_t *ppos) 507{ 508 struct uio_listener *listener = filep->private_data; 509 struct uio_device *idev = listener->dev; 510 DECLARE_WAITQUEUE(wait, current); 511 ssize_t retval; 512 s32 event_count; 513 514 if (!idev->info->irq) 515 return -EIO; 516 517 if (count != sizeof(s32)) 518 return -EINVAL; 519 520 add_wait_queue(&idev->wait, &wait); 521 522 do { 523 set_current_state(TASK_INTERRUPTIBLE); 524 525 event_count = atomic_read(&idev->event); 526 if (event_count != listener->event_count) { 527 if (copy_to_user(buf, &event_count, count)) 528 retval = -EFAULT; 529 else { 530 listener->event_count = event_count; 531 retval = count; 532 } 533 break; 534 } 535 536 if (filep->f_flags & O_NONBLOCK) { 537 retval = -EAGAIN; 538 break; 539 } 540 541 if (signal_pending(current)) { 542 retval = -ERESTARTSYS; 543 break; 544 } 545 schedule(); 546 } while (1); 547 548 __set_current_state(TASK_RUNNING); 549 remove_wait_queue(&idev->wait, &wait); 550 551 return retval; 552} 553 554static ssize_t uio_write(struct file *filep, const char __user *buf, 555 size_t count, loff_t *ppos) 556{ 557 struct uio_listener *listener = filep->private_data; 558 struct uio_device *idev = listener->dev; 559 ssize_t retval; 560 s32 irq_on; 561 562 if (!idev->info->irq) 563 return -EIO; 564 565 if (count != sizeof(s32)) 566 return -EINVAL; 567 568 if (!idev->info->irqcontrol) 569 return -ENOSYS; 570 571 if (copy_from_user(&irq_on, buf, count)) 572 return -EFAULT; 573 574 retval = idev->info->irqcontrol(idev->info, irq_on); 575 576 return retval ? retval : sizeof(s32); 577} 578 579static int uio_find_mem_index(struct vm_area_struct *vma) 580{ 581 struct uio_device *idev = vma->vm_private_data; 582 583 if (vma->vm_pgoff < MAX_UIO_MAPS) { 584 if (idev->info->mem[vma->vm_pgoff].size == 0) 585 return -1; 586 return (int)vma->vm_pgoff; 587 } 588 return -1; 589} 590 591static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 592{ 593 struct uio_device *idev = vma->vm_private_data; 594 struct page *page; 595 unsigned long offset; 596 void *addr; 597 598 int mi = uio_find_mem_index(vma); 599 if (mi < 0) 600 return VM_FAULT_SIGBUS; 601 602 /* 603 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE 604 * to use mem[N]. 605 */ 606 offset = (vmf->pgoff - mi) << PAGE_SHIFT; 607 608 addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset; 609 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) 610 page = virt_to_page(addr); 611 else 612 page = vmalloc_to_page(addr); 613 get_page(page); 614 vmf->page = page; 615 return 0; 616} 617 618static const struct vm_operations_struct uio_logical_vm_ops = { 619 .fault = uio_vma_fault, 620}; 621 622static int uio_mmap_logical(struct vm_area_struct *vma) 623{ 624 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; 625 vma->vm_ops = &uio_logical_vm_ops; 626 return 0; 627} 628 629static const struct vm_operations_struct uio_physical_vm_ops = { 630#ifdef CONFIG_HAVE_IOREMAP_PROT 631 .access = generic_access_phys, 632#endif 633}; 634 635static int uio_mmap_physical(struct vm_area_struct *vma) 636{ 637 struct uio_device *idev = vma->vm_private_data; 638 int mi = uio_find_mem_index(vma); 639 struct uio_mem *mem; 640 if (mi < 0) 641 return -EINVAL; 642 mem = idev->info->mem + mi; 643 644 if (mem->addr & ~PAGE_MASK) 645 return -ENODEV; 646 if (vma->vm_end - vma->vm_start > mem->size) 647 return -EINVAL; 648 649 vma->vm_ops = &uio_physical_vm_ops; 650 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 651 652 /* 653 * We cannot use the vm_iomap_memory() helper here, 654 * because vma->vm_pgoff is the map index we looked 655 * up above in uio_find_mem_index(), rather than an 656 * actual page offset into the mmap. 657 * 658 * So we just do the physical mmap without a page 659 * offset. 660 */ 661 return remap_pfn_range(vma, 662 vma->vm_start, 663 mem->addr >> PAGE_SHIFT, 664 vma->vm_end - vma->vm_start, 665 vma->vm_page_prot); 666} 667 668static int uio_mmap(struct file *filep, struct vm_area_struct *vma) 669{ 670 struct uio_listener *listener = filep->private_data; 671 struct uio_device *idev = listener->dev; 672 int mi; 673 unsigned long requested_pages, actual_pages; 674 int ret = 0; 675 676 if (vma->vm_end < vma->vm_start) 677 return -EINVAL; 678 679 vma->vm_private_data = idev; 680 681 mi = uio_find_mem_index(vma); 682 if (mi < 0) 683 return -EINVAL; 684 685 requested_pages = vma_pages(vma); 686 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) 687 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; 688 if (requested_pages > actual_pages) 689 return -EINVAL; 690 691 if (idev->info->mmap) { 692 ret = idev->info->mmap(idev->info, vma); 693 return ret; 694 } 695 696 switch (idev->info->mem[mi].memtype) { 697 case UIO_MEM_PHYS: 698 return uio_mmap_physical(vma); 699 case UIO_MEM_LOGICAL: 700 case UIO_MEM_VIRTUAL: 701 return uio_mmap_logical(vma); 702 default: 703 return -EINVAL; 704 } 705} 706 707static const struct file_operations uio_fops = { 708 .owner = THIS_MODULE, 709 .open = uio_open, 710 .release = uio_release, 711 .read = uio_read, 712 .write = uio_write, 713 .mmap = uio_mmap, 714 .poll = uio_poll, 715 .fasync = uio_fasync, 716 .llseek = noop_llseek, 717}; 718 719static int uio_major_init(void) 720{ 721 static const char name[] = "uio"; 722 struct cdev *cdev = NULL; 723 dev_t uio_dev = 0; 724 int result; 725 726 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); 727 if (result) 728 goto out; 729 730 result = -ENOMEM; 731 cdev = cdev_alloc(); 732 if (!cdev) 733 goto out_unregister; 734 735 cdev->owner = THIS_MODULE; 736 cdev->ops = &uio_fops; 737 kobject_set_name(&cdev->kobj, "%s", name); 738 739 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); 740 if (result) 741 goto out_put; 742 743 uio_major = MAJOR(uio_dev); 744 uio_cdev = cdev; 745 return 0; 746out_put: 747 kobject_put(&cdev->kobj); 748out_unregister: 749 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); 750out: 751 return result; 752} 753 754static void uio_major_cleanup(void) 755{ 756 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); 757 cdev_del(uio_cdev); 758} 759 760static int init_uio_class(void) 761{ 762 int ret; 763 764 /* This is the first time in here, set everything up properly */ 765 ret = uio_major_init(); 766 if (ret) 767 goto exit; 768 769 ret = class_register(&uio_class); 770 if (ret) { 771 printk(KERN_ERR "class_register failed for uio\n"); 772 goto err_class_register; 773 } 774 return 0; 775 776err_class_register: 777 uio_major_cleanup(); 778exit: 779 return ret; 780} 781 782static void release_uio_class(void) 783{ 784 class_unregister(&uio_class); 785 uio_major_cleanup(); 786} 787 788/** 789 * uio_register_device - register a new userspace IO device 790 * @owner: module that creates the new device 791 * @parent: parent device 792 * @info: UIO device capabilities 793 * 794 * returns zero on success or a negative error code. 795 */ 796int __uio_register_device(struct module *owner, 797 struct device *parent, 798 struct uio_info *info) 799{ 800 struct uio_device *idev; 801 int ret = 0; 802 803 if (!parent || !info || !info->name || !info->version) 804 return -EINVAL; 805 806 info->uio_dev = NULL; 807 808 idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL); 809 if (!idev) { 810 return -ENOMEM; 811 } 812 813 idev->owner = owner; 814 idev->info = info; 815 init_waitqueue_head(&idev->wait); 816 atomic_set(&idev->event, 0); 817 818 ret = uio_get_minor(idev); 819 if (ret) 820 return ret; 821 822 idev->dev = device_create(&uio_class, parent, 823 MKDEV(uio_major, idev->minor), idev, 824 "uio%d", idev->minor); 825 if (IS_ERR(idev->dev)) { 826 printk(KERN_ERR "UIO: device register failed\n"); 827 ret = PTR_ERR(idev->dev); 828 goto err_device_create; 829 } 830 831 ret = uio_dev_add_attributes(idev); 832 if (ret) 833 goto err_uio_dev_add_attributes; 834 835 info->uio_dev = idev; 836 837 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { 838 ret = devm_request_irq(idev->dev, info->irq, uio_interrupt, 839 info->irq_flags, info->name, idev); 840 if (ret) 841 goto err_request_irq; 842 } 843 844 return 0; 845 846err_request_irq: 847 uio_dev_del_attributes(idev); 848err_uio_dev_add_attributes: 849 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 850err_device_create: 851 uio_free_minor(idev); 852 return ret; 853} 854EXPORT_SYMBOL_GPL(__uio_register_device); 855 856/** 857 * uio_unregister_device - unregister a industrial IO device 858 * @info: UIO device capabilities 859 * 860 */ 861void uio_unregister_device(struct uio_info *info) 862{ 863 struct uio_device *idev; 864 865 if (!info || !info->uio_dev) 866 return; 867 868 idev = info->uio_dev; 869 870 uio_free_minor(idev); 871 872 uio_dev_del_attributes(idev); 873 874 device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); 875 876 return; 877} 878EXPORT_SYMBOL_GPL(uio_unregister_device); 879 880static int __init uio_init(void) 881{ 882 return init_uio_class(); 883} 884 885static void __exit uio_exit(void) 886{ 887 release_uio_class(); 888} 889 890module_init(uio_init) 891module_exit(uio_exit) 892MODULE_LICENSE("GPL v2"); 893